Answer:
We're asked to find the molar concentration of the
NaCl
solution given some titration data.
Let's first write the chemical equation for this reaction:
NaOH
(
a
q
)
+
HCl
(
a
q
)
→
NaCl
(
a
q
)
+
H
2
O
(
l
)
Using the molarity equation, we can find the number of moles of
HCl
that reacted:
molarity
=
mol solute
L soln
mol solute
=
(
molarity
)
(
L soln
)
mol HCl
=
(
0.105
mol
L
)
(
0.0250
L
)
=
0.00263
mol HCl
(volume converted to liters)
Now, using the coefficients of the chemical reaction, we can determine the number of moles of
NaOH
that reacted:
0.00263
mol HCl
(
1
l
mol NaOH
1
mol HCl
)
=
0.00263
mol NaOH
Lastly, we'll use the molarity equation (using given volume of
NaOH soln
) again to determine the molarity of the sodium hydroxide solution:
molarity
=
mol solute
L soln
M
NaOH
=
0.00263
l
mol
0.315
l
L
=
0.00833
M
(volume converted to liters)